1. Field of the Invention
This invention relates to a technique for data transfer between a host device and a slave device, for example, to a storage control system such as a RAID system, and to a channel control device which can be installed in such a storage control system.
2. Description of the Related Art
In for example a database system such as a data center which handles large volumes of data, a storage control system, provided separately from the host computer, manages data. This storage control system is for example a disk array system such as a RAID (Redundant Array of Independent Inexpensive Disks) system, in which numerous storage devices are arranged in an array.
As has for example been disclosed in Japanese Patent Laid-open No. 2003-316713, such a storage control system, by comprising network channel adapters (hereafter “CHN”) to process I/O requests in file units, can become a NAS (Network Area Storage) system. Further, this storage control system comprises disks, disk adapters (DKAs), and cache memory which stores data shared by CHNs and DKAs and recorded on disks.
According to the above patent publication, a CHN is provided with memory, and a data buffer used for file data caching and similar exists in this memory. Hence data transfer between a NAS client and cache memory is performed via the data buffer in this memory. If the speed of this data transfer can be increased, greater convenience can be expected to result.